A dosimeter of the kind referred to above for detecting carbon monoxide is described in U.S. Pat. No. 3,112,999.
Tubular dosimeters having a layer in the form of a tubular shell permeable to the substance to be detected provide an increased detection sensitivity when compared to tubular dosimeters wherein only the end of the tube is permeable to the substance to be detected. This increased detection sensitivity of tubular dosimeters is provided because the substance to be detected is provided with a far greater pass-through surface to the collecting reagent.
The known dosimeters, however, have the disadvantage that only such substances to be detected can be collected which can be absorbed directly at the collecting reagent or otherwise go into a bonding reaction. The detection of other substances which is likewise desirable is not possible with the known dosimeter.